Expression and Role of PAICS, a De Novo Purine Biosynthetic Gene in Prostate Cancer

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135186/1/pros23243.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135186/2/pros23243_am.pd

Vectors expressing efficient RNA decoys achieve the long-term suppression of specific microRNA activity in mammalian cells

Whereas the strong and stable suppression of specific microRNA activity would be essential for the functional analysis of these molecules, and also for the development of therapeutic applications, effective inhibitory methods to achieve this have not yet been fully established. In our current study, we tested various RNA decoys which were designed to efficiently expose indigestible complementary RNAs to a specific miRNA molecule. These inhibitory RNAs were at the same time designed to be expressed in lentiviral vectors and to be transported into the cytoplasm after transcription by RNA polymerase III. We report the optimal conditions that we have established for the design of such RNA decoys (we term these molecules TuD RNAs; tough decoy RNAs). We finally demonstrate that TuD RNAs induce specific and strong biological effects and also show that TuD RNAs achieve the efficient and long-term-suppression of specific miRNAs for over 1 month in mammalian cells

spot 003 thymidylate synthase maintains the undifferentiated state of aggressive breast cancers

Introduction De-differentiation is a highly lethal feature of aggressive breast cancers (BC), and is achieved through the epithelial-to-mesenchymal transition (EMT) and the cancer stem cell (CSC) programs. Targeting the mechanisms controlling BC de-differentiation can lead to more effective therapeutics. Recent studies indicated that nucleotide metabolism can regulate cancer stemness and EMT. Here we investigated the expression of the nucleotide metabolism enzyme and drug target thymidylate synthase (TS) in the BC subtypes and analysed its impact on BC de-differentiation. Material and methods Cells with TS knockdown and overexpression were tested in vitro and in vivo. Proteins were analysed by western blot, FACS and ELISA. Differential gene expression in TS-deficient cells was determined by RNA-seq. Immunohistochemistry (IHC) was used to stain samples from patients with different BC subtypes. Results and discussions TS mRNA expression was found to be significantly differentially expressed among the BC subtypes, exhibiting the highest levels in aggressive triple-negative BC (TNBC). shRNA-mediated TS knockdown in TNBC cell lines (n=3) increased the population of differentiated cells (CD24high) and strongly attenuated the stem-like phenotype, like the formation of mammospheres from single cells and the migration in a cell culture wound. TS-deficient cells also showed an altered ability to form metastasis in vivo, consistent with previous observations in EMT-repressed BC cells. A rescue experiment performed by overexpressing either a wild-type or catalytically inactive TS indicated that the enzymatic activity was essential for the maintenance of the BCSC phenotype. Along with a strong repression of EMT-signature genes, RNA-seq profiling indicated a reduction of inflammatory and NF-κB signalling pathways in TS deficient cells, which dramatically reduced IL-1β production and secretion. A TS-specific gene signature was generated, which significantly associated with worst survival in BC patients. IHC staining on FFPE samples from a series of BC patients (n=120) confirmed higher TS expression in tumours that were poorly differentiated and in TNBC. Conclusion We discovered a novel role for the TS enzyme in the maintenance of a de-differentiated and stem-like state of BC. These findings may not only open the possibility to study in-depth the role of nucleotide metabolism at the crossroad between proliferation and differentiation, but may provide the rationale for novel drug combinations with TS-inhibiting agents for the treatment of BC

Inhibition of BET proteins and epigenetic signaling as a potential treatment for osteoporosis

International audienceHistone modifications are important for maintaining the transcription program. BET proteins, an important class of " histone reading proteins " , have recently been described as essential in bone biology. This study presents the therapeutic opportunity of BET protein inhibition in osteoporosis. We find that the pharmacological BET protein inhibitor JQ1 rescues pathologic bone loss in a post-ovariectomy osteoporosis model by increasing the trabecular bone volume and restoring mechanical properties. The BET protein inhibition suppresses osteoclast differentiation and activity as well as the osteoblastogenesis in vitro. Moreover, we show that treated non-resorbing osteoclasts could still activate osteoblast differentiation. In addition, specific inhibition of BRD4 using RNA interference inhibits osteoclast differentiation but strongly activates osteoblast mineralization activity. Mechanistically, JQ1 inhibits expression of the master osteoclast transcription factor NFATc1 and the transcription factor of osteoblast Runx2. These findings strongly support that targeting epigenetic chromatin regulators such as BET proteins may offer a promising alternative for the treatment of bone-related disorders such as osteoporosis

Anti-inflammatory and cell proliferative effect of the 1270 nm laser irradiation on the BALB/c Nude mouse model involves activation of the cell antioxidant system

Recently, many interdisciplinary community researchers have focused their efforts on study of the low-level light irradiation effects (photobiomodulation, PBM) as a promising therapeutic technology. Among the priorities, a search of new wavelength ranges of laser radiation to enhance the laser prospects in treatment of autoimmune and cancer diseases commonly accompanied by disorders in the antioxidant system of the body. The laser wavelengths within 1265-1270 nm corresponds to the maximum oxygen absorption band. Therefore, PBM effects on a model organism within this spectrum range are of particular interest for preclinical research. Here, we report comprehensive biomolecular studies of the changes in the BALB/c nude mice skin after an exposure to the continuous laser radiation at the 1270 nm wavelength and energy densities of 0.12 and 1.2 J/cm2. Such regime induces both local and systemic PBM effects, presumably due to the short-term increase in ROS levels, which in turn activate the cell antioxidative system

A multi-targeted approach to suppress tumor-promoting inflammation

Cancers harbor significant genetic heterogeneity and patterns of relapse following many therapies are due to evolved resistance to treatment. While efforts have been made to combine targeted therapies, significant levels of toxicity have stymied efforts to effectively treat cancer with multi-drug combinations using currently approved therapeutics. We discuss the relationship between tumor-promoting inflammation and cancer as part of a larger effort to develop a broad-spectrum therapeutic approach aimed at a wide range of targets to address this heterogeneity. Specifically, macrophage migration inhibitory factor, cyclooxygenase-2, transcription factor nuclear factor-κB, tumor necrosis factor alpha, inducible nitric oxide synthase, protein kinase B, and CXC chemokines are reviewed as important antiinflammatory targets while curcumin, resveratrol, epigallocatechin gallate, genistein, lycopene, and anthocyanins are reviewed as low-cost, low toxicity means by which these targets might all be reached simultaneously. Future translational work will need to assess the resulting synergies of rationally designed antiinflammatory mixtures (employing low-toxicity constituents), and then combine this with similar approaches targeting the most important pathways across the range of cancer hallmark phenotypes